JPH0545373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a robot assembly device that allows a single robot to perform assembly operations on various work surfaces of a workpiece.

(Prior art) As a characteristic of robot operation, for example, as shown in Fig. 1, a workpiece is moved from one point A to another point B.
In the case of work to move the workpiece, the robot's hand first moves to the position directly below the workpiece, then the hand descends to chuck the workpiece, and then the hand ascends and moves the workpiece to the position directly below point B. Generally, the hand descends and releases the workpiece. This is because robots that move linearly are easier to control and can operate at high speeds.

Therefore, in assembly and other tasks performed by robots, the robot performs three degrees of freedom: two degrees of freedom for positioning in a plane parallel to the work plane, and one degree of freedom for positioning linearly in a direction perpendicular to the work plane. It is common to control axes (in some cases, four axes including one degree of freedom of rotation around an axis in a direction perpendicular to the work plane).

By the way, there was a system as shown in FIG. 2 in which work such as assembly was performed by a robot on workpieces carried by a conveyor. This is carried on a conveyor 1 with a robot 2 placed near the conveyor 1,
This is a type of robot in which work such as assembly is performed on works 3 and 4 that are positioned and stopped within the work area of the robot 2. In this type, for the reasons mentioned above, the robot 2 is positioned on a plane parallel to the working plane, and then moves in a direction perpendicular to said plane. However, with this model, there would be no problem if all the working planes were parallel, but if the working planes were not parallel, it was impossible to work on the back side of the workpiece.

Therefore, as shown in FIG. 3, each work surface 5a,
5b, 5c compatible robots 6A, 6
B, 6C has been used to overcome the above drawbacks. However, as the number of robots increases, there are drawbacks such as increased costs and increased area occupied by the robots.

Furthermore, if one robot is to handle work surfaces that are not parallel to each other, it is essential to increase the degree of freedom, which inevitably increases costs, degrades accuracy, and reduces operating speed. Also, in this case, the workpiece may be relatively large or there may be places where it is impossible to work depending on the shape of the workpiece, and if the linearity of robot movement is lost due to the increased degree of freedom, complex path control will be required. I'm getting old.

Previously, as assembly equipment using robots, JP-A-58
As shown in No. 165980, a device is disclosed that positions and fixes the workpiece from the lateral direction using an engine clamp 27 fixed on the turntable of the workpiece, and further rotates the positioned workpiece.

However, since the workpiece is fixed only in the horizontal direction, it is not possible to process the entire horizontal surface of the workpiece, and when it is rotated, the workpiece may shake due to its inertia, or during machining. There was a problem that the tool would swing due to the force of pressing against the workpiece, such as a tool.

Furthermore, when the workpiece is placed and fixed on the turntable, the reworkpiece is transported by a robot with orthogonal coordinates, which poses a problem in that the apparatus itself becomes expensive.

(Objective) An object of the present invention is to provide an inexpensive assembly device that can perform assembly work on the entire horizontal work surface at high speed with one robot.

(Embodiment) Next, a first embodiment of the present invention shown in FIGS. 4 to 7 will be described in detail. Reference numeral 10 denotes a rectangular parallelepiped-shaped workpiece (an outer box of a gear device), on which stud bolts 11 are lightly screwed in advance on four sides. 12 is a conveyor that conveys the work 10. Reference numeral 13 denotes a base disposed on one side of the conveyor 12, and a slider 17 that is parallel to the slider 17 that slides linearly at right angles to the conveyor 12 along a pair of guide rails 15 and 16 of the robot mounting base 14 fixed thereon. A robot 18 having an arm that rotates about two axes is mounted so that its rotation axis is parallel to the sliding direction of the slider 17. 19 is an air cylinder that drives the slider 17. A nut runner 21 is fixed to the tip of the work arm 20 of the robot 18, and a stud bolt 11 is fixed to the tip of the rotating shaft 22.
The robot 18 connects the socket 23 to
It is mounted parallel to the axis of rotation. 24 is a pallet placed on the conveyor 12, and the workpiece 10 is positioned by a positioning jig 25 fixed to the upper surface. A lifter 27 is disposed within the conveyor 12 at a position facing the base 13 and is driven upward by an air cylinder 26. A plurality of rollers 28 are disposed on the upper surface of the lifter 27 so as to rotate toward the base 13. ing. Reference numeral 29 denotes an underframe fixed to the upper right side of the base 13, which has a work space between it and the base 13 in which the workpiece 10 can be placed.An index 31 driven by a motor 30 is disposed on the top surface, and its output shaft 3
The lower end of the output shaft 32 is fixed to a disk 34, which has a locating pin 33 protruding from its lower surface. A lifter 36 that is driven upward by an air cylinder 35 is disposed within the base 13 facing the disc 34, and a locate pin 37 is provided protruding from the upper surface of the lifter 36. The guide 4 has a plurality of rollers 38 and 39 before and after the locate pin 37.
0,41 match the front and rear width of pallet 24, and roll 3
8 and 39 are arranged in parallel to the roller 28 so as to rotate in the same direction. 42 is a plate linearly driven in parallel with the guides 40 and 41 by an air cylinder 43 disposed on the upper left surface of the base 13;
A hook 45 is attached to a rotary actuator 44 fixed to the plate 42. Reference numeral 46 denotes a protrusion protruding from the pallet 24, with which the hook 45 engages.

Next, the effect will be explained. A pallet 24 with a workpiece 10 attached thereto is conveyed on the conveyor 12, and when it reaches a lifter 27, the pallet 24 is stopped by a stop jig (not shown). Next, the lifter 27 is moved up the pallet 24 by the air cylinder 26, separated from the conveyor 12, and stopped when the lifter 27 is at the same height as the guides 40, 41. Next, the air cylinder 43 is activated, and the plate 42 approaches the pallet 24 and stops when it reaches a predetermined position.Then, the rotary actuator 44 is activated, and the hook 45 engages with the protrusion 46 on the pallet 24. The air cylinder 43 then operates in a direction to draw the pallet 24 toward the base 13. And palette 24 is base 13
It is pulled into a space between the index mount 29 and the index mount 29, and is stopped by a stopper (not shown) provided on the base 13. At this time, the pallet 24 moves the roller 28 of the lifter 27 and the guides 40, 41 to the roller 3.
It is performed smoothly by sliding on 8,39. Then, the hook 45 separates from the protrusion 46 and the plate 42 retreats. Next, the air cylinder 35 is operated and the lifter 36 is raised to lift the pallet 24 from below. At this time, the locate pin 37 engages with a hole (not shown) formed in the pallet 24, thereby achieving accurate positioning. Next, lifter 3
6 further rises, the upper part of the workpiece 10 contacts the disk 34, and the locate pin 33 engages with the workpiece 10.
Next, the workpiece 10 is rotated about the output shaft 32 by the index 31, and the work surface 10a of the workpiece 10 is set perpendicular to the rotation axis of the robot 18. At this time, lifter 3
6 rotates with a cylinder rod (not shown) of an air cylinder 35 serving as a rotation axis. Next, the robot 18 operates and stops when the socket 23 of the work arm 20 comes over the tip of one shaft of the stud bolt 11 on the work surface 10a of the workpiece 10. Next, the air cylinder 19 is operated, the robot 18 slides linearly, and when the socket 23 approaches the stud bolt 11, the rotary shaft 22 rotates and chucks the stud bolt 11 to perform a fastening operation. After the fastening is completed, the robot 18 moves back and repeats the above-mentioned operation to complete the fastening work of the stud bolts 11 on the entire work surface 10a. Next, the index is actuated to rotate the workpiece 10 so that the next work surface of the workpiece 10 is set perpendicular to the axis of rotation of the robot 18. Then, the above-mentioned fastening work is performed.

When the four-sided fastening work is completed in this manner, the lifter 36 is lowered by the air cylinder 35 to remove the workpiece 10 from the disk 34 and place the pallet 24 on the guides 40 and 41. Next, the plate 42 is advanced by the air cylinder 43, the hook 45 is engaged with the protrusion 46 of the pallet 24, and the lifter 27 in the conveyor 12 is moved forward.
After being pushed back up, the lifter 27 descends and returns the pallet 24 onto the conveyor 12, completing one process.

In addition, instead of tightening stud bolts, it can also be used for assembly work such as inserting various parts, and instead of a nut runner, a hand is attached to the tip of the work arm and this hand is rotated on an axis parallel to the rotation axis of the robot. By doing so, the number of axes of the robot increases by one, but it is also possible to handle irregularly shaped workpieces.

Furthermore, by providing an ATC device such as that used in a well-known machining center in which different sockets, hands, etc. are used in one robot, it is possible to handle various tasks.

(Effects) According to the present invention, a workpiece lifting means disposed at a lower position of a workpiece conveyor, a means for moving and placing the raised workpiece on a lifter, a means for lifting the lifter, and a raised lifter. It has an indexing means that presses and holds the upper surface of the workpiece and stops rotating the workpiece in a direction perpendicular to the work axis of the horizontal multi-joint robot, and a movement means that moves the entire robot in the direction of the work axis. The assembly work can be performed stably, the entire horizontal work surface can be assembled at high speed, and it can be provided at low cost.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the basics of robot operation, Fig. 2 is a perspective view of a first comparative example of a conventional robot assembly device, Fig. 3 is a perspective view of a second comparative example of the same, and Fig. 4 is a perspective view of a conventional robot assembly device. FIG. 5 is a perspective view of an example of a work to be carried out, FIG. 5 is a cutaway perspective view of the main part of the first embodiment of the present invention, FIG. 6 is a plan view of the same, and FIG. 7 is a cutaway front view of the main part. 13... Base, 14... Robot mounting base, 1
5, 16... Guide rail, 17... Slider, 18... Robot, 19... Air cylinder, 20... Work arm, 21... Nut runner, 22... Rotating shaft, 23... Socket, 31...
...Index, 32...Output shaft, 34...Disc, 35...Air cylinder, 36...Lifter.

Claims (1)

[Claims] 1. A workpiece lifting means disposed at a fixed position below the workpiece conveyor, a means for moving and placing the raised workpiece on a lifter, a means for raising the lifter, and a means for pressing the upper surface of the workpiece on the lifted lifter. indexing means for holding and rotating and stopping the workpiece in a direction perpendicular to the work axis of the horizontal articulated robot;
An assembly device using a robot, which includes a moving means for moving the entire robot in the direction of a working axis.